3/4 Ton Truck Lowering - Too Low To Tow? Never!

Drop your rig without reservation

If you’re reading any sort of performance magazine, like Truckin’, then there’s a good chance that you have a hard time leaving anything stock, or as-delivered from the factory. You like to personalize and customize your rides and we’re no different. Just because you bought a truck to tow things and haul cargo doesn’t mean that you can’t have it look the way you want.

We recently came across a tow rig that was begging to be dropped. It was already wearing a set of sporty Raceline 22-inch wheels with Falken low-profile rubber, but it needed the stance to match. After doing a bit of research, we found that there didn’t seem to be a whole lot of three-quarter-ton lowering kits on the market, and basically none that were specific to our 2000 GMC Sierra C2500 classic Crew Cab truck. Chances are, however, that your 2500-series pickup utilizes many of the same components as its bigger 3500 brethren. And there are plenty of kits for those.

To accomplish our lowered stance, we went to DJM Suspension, who has been dropping trucks for a few decades. The folks there know what they are doing, and the relative ease of installation of the company’s products showed this.

DJM offers two kits for your fullsize Chevy or GMC. There’s the nice and easy 3-4 drop that utilizes drop spindles with a hanger/shackle kit in the rear. If you need to mow the pavement with your front bumper, DJM has the Slam kit, which drops your ride 5 inches in the front and 7 inches in the rear. This is accomplished by using drop spindles and 2-inch lowering springs up front, with an axle flip kit out back.

We went with the 3-4 drop given the sizeable wheel/tire package that we were already using. For the front end, the prescription was a simple set of drop spindles and accompanying shock absorbers. Pull the factory parts off, mount the new spindle, and bolt the parts back on. The reward was instant the minute the wheels hit the ground.

Out back, the installation of hangers and shackles is a bit more involved, but equally rewarding. Removing the factory rivets that hold the stock spring hangers on is challenging, but with the right tools, more easily accomplished.

After setting the ride height to where we thought it should be, we looked at giving the back half of the truck a little support in the way of an air spring setup. Firestone Industrial Products has been in the air spring game a long time, and manufactures them for everything from tractor-trailers on down to your mini-truck.

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In lowering your truck, you’re removing some of the factory rake or preload in the rear suspension that prevents the truck from buckling down when the payload hits the bed. Firestone’s Sport Rite air helper springs mount between the frame and the leaf springs to support the added weight and keep the load level.

With the truck lowered, you often don’t have the room between the two to fit an air spring, and that was the situation we ran into, so we went with the 2516 kit that mounts the air springs outside of the actual frame, but on top of the leaf spring. The kit retails for $300, and you can find the nearest Firestone distributor right on the company’s website.

One other thing you’ll want to consider is the weight rating of your tires. Though the rubber band-like profile looks great, oftentimes those sorts of tires are not rated to support a lot of weight. Our Falken Azenis tires barely met our self-imposed minimum of a 5,000-pound tow capacity, and we contemplated moving to something a bit more highly rated, but given the fact that we only tow occasionally, we’ll save the tire upgrade for the next time we need to purchase rubber.

That being said, there’s no reason why you can’t lower your three-quarter or one-ton truck and still deliver the payload that your truck is capable of carrying, so check out how we made it happen for our 2000 Crew Cab.

1. DJM has the easy solution to drop almost any truck. Ours included the DS2057-3 drop spindles, HS1122-4 hanger and shackle kit, 1315 front Calmax shock absorbers, and the 2200 rear shocks. These components combined offer a 3-inch front, and 4-inch rear drop, and retail for a little over $700. If you’re performing this swap on a C3500, then you’ll want to verify that you have the correct hangers before you start, as the factory hangers offered two sets of rivet locations.

1. DJM has the easy solution to drop almost any truck. Ours included the DS2057-3 drop spi

2. After hitting all of the front suspension fasteners with some penetrating oil, we removed the tie-rod end first.

2. After hitting all of the front suspension fasteners with some penetrating oil, we remov

3. The caliper bolts were next. Have a bungee cord or coat hanger handy to hang the caliper up and out of the way while you complete the rest of the spindle swap.

3. The caliper bolts were next. Have a bungee cord or coat hanger handy to hang the calipe

4. Next, we removed the rotor by taking out the cotter pin, bearing nut, and wheel bearing.

4. Next, we removed the rotor by taking out the cotter pin, bearing nut, and wheel bearing

5. The toughest part of the spindle swap was breaking the ball joints free. We were able to loosen the nuts up and then hit the spindle with a hammer where the ball joint stud goes through the collar. If you’re lucky, they will break loose without much trouble. If not, then you may need to use a manual or air-powered fork to split them. Take this time to inspect the ball joints as well.

5. The toughest part of the spindle swap was breaking the ball joints free. We were able t

6. The DJM spindle bolted right back in place of the original.

7. With the new spindles on, our front brake lines ran directly into the spindle itself, so we gently pried them inward to swoop around the knuckle. Be sure to check for interference throughout the truck’s ranges of steering and suspension movement.

8. The Calmax Super Shox were up next, and simply bolted in place of the factory dampers. There’s just one, vey easy to reach, top nut, and then two bolts down below. Calmax shocks are twin-tube, nitrogen-filled hydraulic shock absorbers that DJM builds for all of its lowering kits. They also offer factory replacement Calmax units for stock trucks and SUVs as well.

8. The Calmax Super Shox were up next, and simply bolted in place of the factory dampers.

9. It’s possible to accomplish the rear suspension parts swap with the bed on, but it’s much easier to do it if you pull the bed. There are eight large bolts holding it to the frame, and you’ll also have to remove the fuel filler neck seen here, as well as the taillight/towing wiring harness at the back of the bed.

10. Having the bed off makes it much easier to get to the hanger rivets, which will take a bit of work to remove, especially if you don’t have a good air chisel. Special thanks goes to Brian Bohnsack (left) and James Zanata (right), as well as Mark Johnson and Rob Baldwin for performing the installation with us.

10. Having the bed off makes it much easier to get to the hanger rivets, which will take a

11. Here, you can see the rivets that secure the leaf spring to the frame. Unless you build buildings for a living, these are some of the largest you will see, and as you might expect, they are equally hard to remove. The parking brake cables in the foreground must also be removed and swapped over to the new DJM hanger.

11. Here, you can see the rivets that secure the leaf spring to the frame. Unless you buil

12. and 13. If you have a good air chisel, then you can probably cut a plus sign in the head of the rivet, and then just shear it off after that. Our chisel didn’t have the stones, so we used a cut-off wheel on the passenger side to take of the head, and then the air chisel to push the rivet through. On the passenger side, we hit it with a drill and the air chisel to cut down on the sparks generated near the gas tank opening, and to speed up the overall installation time.

12. and 13. If you have a good air chisel, then you can probably cut a plus sign in the he

12. and 13. If you have a good air chisel, then you can probably cut a plus sign in the head of the rivet, and then just shear it off after that. Our chisel didn’t have the stones, so we used a cut-off wheel on the passenger side to take of the head, and then the air chisel to push the rivet through. On the passenger side, we hit it with a drill and the air chisel to cut down on the sparks generated near the gas tank opening, and to speed up the overall installation time.

12. and 13. If you have a good air chisel, then you can probably cut a plus sign in the he

14. Here you can see the difference between the factory hanger and the DJM piece. The aftermarket unit will actually use the upper four boltholes to achieve the desired drop effect.

14. Here you can see the difference between the factory hanger and the DJM piece. The afte

15. In order for the hanger to fit flatly against the frame, we had to section the forward bed supports.

15. In order for the hanger to fit flatly against the frame, we had to section the forward

16. We then bolted the new hanger in place, and refit the brake cable to the included bracket. When you have the leaf springs off the truck, you have the option, at least with the Chevy/GMC trucks, of removing the helper spring to drop the ride height another inch. We opted to leave ours in at this time to see what the ride height would be.

16. We then bolted the new hanger in place, and refit the brake cable to the included brac

17. The rear shackles were simple to remove and replace. Be sure to just slightly tighten the bolts until you get the truck back on the ground. Once the full weight of the vehicle is on the suspension, then you can torque them to 70 lb-ft.

17. The rear shackles were simple to remove and replace. Be sure to just slightly tighten

18. With the bed off, it’s extremely easy to swap out the factory rear shocks for the new Calmax units.

18. With the bed off, it’s extremely easy to swap out the factory rear shocks for the new

19. To make sure our load stays level, we opted to install this Sport Rite air spring kit (PN 2516) from Firestone Industrial products, which retails for about $300.

19. To make sure our load stays level, we opted to install this Sport Rite air spring kit

20. To start the air spring installation, we first removed the 1-inch-thick helper springs. This dropped the rear ride height another inch, which was needed, and it also allows the included carriage bolts to extend past the spring pack so you can bolt the lower spring bracket together.

20. To start the air spring installation, we first removed the 1-inch-thick helper springs

21. We grabbed an air spring and bolted up the top mounting bracket using the supplied hardware. We also needed to install the air fitting in the top of the spring at this time.

21. We grabbed an air spring and bolted up the top mounting bracket using the supplied har

22. You’ll want to make sure that you truck has the required clearance before drilling. Our kit required 6.5 inches from the top of the frame to the top of the leaf spring, as well as 6.5 inches from the framerail to the inside rim edge. The top bracket must not extend above the top of the framerail, and here you can see that we did not have enough room when mounting the assembly behind the axle. Mounting it in front, however offered the necessary space, and kept the assembly more perpendicular to the ground.

22. You’ll want to make sure that you truck has the required clearance before drilling. Ou

23. We attached the spring clamp to the lower bracket using the supplied carriage bolts. As you can see, had we not removed the helper spring, the bolts would not have been long enough. We felt the truck still had a rake after lowering it initially, so off came the helper springs.

23. We attached the spring clamp to the lower bracket using the supplied carriage bolts. A

24. You can get quite creative with the placement of the air valves, but we prefer not to make any permanent mods to the body or chassis, so the trailer plug bracket was the perfect spot.

24. You can get quite creative with the placement of the air valves, but we prefer not to

25. With the holes drilled, we inserted the air tubing into the fittings, and then mounted the fittings to their final destination.

25. With the holes drilled, we inserted the air tubing into the fittings, and then mounted

26. We’ve seen people actually drill through their bumpers to mount air line valves, but the last thing you want to do is put them somewhere you might step on them.

26. We’ve seen people actually drill through their bumpers to mount air line valves, but t

BEFORE
27. and 28. The Raceline wheels definitely push the look of our three-quarter-ton ride towards the racy end of the spectrum. With the ride height dropped, we have a lower center of gravity and closed the fender-to-tire gap to remove the four-wheel-drive look. And with the Firestone air spring setup, we can keep on towing and hauling, which is why you buy a heavy-duty truck in the first place.

BEFORE
27. and 28. The Raceline wheels definitely push the look of our three-quarter-to

AFTER
27. and 28. The Raceline wheels definitely push the look of our three-quarter-ton ride towards the racy end of the spectrum. With the ride height dropped, we have a lower center of gravity and closed the fender-to-tire gap to remove the four-wheel-drive look. And with the Firestone air spring setup, we can keep on towing and hauling, which is why you buy a heavy-duty truck in the first place.

AFTER
27. and 28. The Raceline wheels definitely push the look of our three-quarter-ton